MANTECAL, Venezuela — Stealing the eggs from an enraged, 10-foot crocodile is a delicate operation.

“If you don’t have your guard up, this crocodile can jump out of the water onto the sand, and in the same motion she can catch you,” said Luis Rattia, 37, who runs a hatchery at the government-owned El Frío ranch, part of a sputtering effort to save the Orinoco crocodile, the largest predator in South America, from extinction.

There were once millions of Orinoco crocodiles living along the banks of the great river, which gave them their name, and its tributaries in Venezuela and eastern Colombia.

But the fearsome animals were nearly done in by fashion. They were hunted almost to extermination from the 1920s to the 1950s to feed a worldwide demand for crocodile-skin boots, coats, handbags and other items. Today, biologists estimate that there are only about 1,500 Orinoco crocodiles left in the wild, nearly all of them in Venezuela.

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Álvaro Velasco, a specialist, at a government-run ranch in Venezuela that breeds the Orinoco crocodile.Credit
Meridith Kohut for The New York Times

The El Frío ranch, which was expropriated by Venezuela’s government in 2009, represents the hopes and the frustrations of conservationists who have worked to save the animal for years, often at cross purposes with a government that frequently views them with suspicion. Thanks in part to that disconnect, efforts to save the animal suffer from a lack of coordination and money, imperiling their already limited success.

When the naturalist and explorer Alexander von Humboldt traveled through the Venezuelan plains in 1800, he found crocodiles lining the riverbanks, with the largest males measuring up to 24 feet long.

José Gumilla, an 18th-century priest who wrote a natural history of the Orinoco, told of the fear the huge crocodile inspired. “It is ferocity itself,” he wrote, “the crude offspring of the greatest monstrosity, the horror of every living thing; so formidable that if a crocodile were to look in a mirror it would flee trembling from itself.”

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Mr. Velasco holding babies.Credit
Meridith Kohut for The New York Times

It is easy to see what Father Gumilla was talking about. On another government-run ranch near El Frío, a large crocodile lay in the shallows of a rushing stream one recent evening, its eyes nearly shut, its mouth open in what looked like a cruel smile. With a scaly dragon’s back; spiky tail; long, white teeth; and fat, wormlike belly, it seemed like something out of a myth. Suddenly, it moved with lightning quickness, thrashing its tail and gorging on a fish that swam within range of its snapping jaws.

The first concerted efforts to breed the Orinoco crocodile were started in the 1980s by conservation-minded ranchers whose lands straddled the animal’s once extensive territory.

Then, in 1990, scientists began releasing young crocodiles into rivers on the El Frío ranch, where wild crocodiles had not been seen in at least two decades. Today, researchers estimate that as many as 400 crocodiles inhabit the ranch, forming an entirely new population that shows the species’ ability to recover if conditions are right.

“This is the great success of the program,” said Álvaro Velasco, a former government biologist who heads an independent group of crocodile specialists. “The achievement is that there were no crocodiles here, and now there is a population that can reproduce itself.”

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Álvaro Velasco viewing tanks holding baby crocodiles. Biologists estimate there are 1,500 Orinoco crocodiles in the wild.Credit
Meridith Kohut for The New York Times

He stood with Mr. Rattia on a recent morning at the edge of a wide lagoon on the ranch, as a large male crocodile surfaced 50 feet offshore. Mr. Velasco said that the animal, roughly 15 feet long, was about 20 years old, placing it among one of the first generations of crocodiles released here.

The program at El Frío was begun when the 153,000-acre ranch was in private hands, as part of a research station started in the 1970s that brought scientists from around the world to study the ecology of the Venezuelan plains.

During a wave of nationalizations carried out by the country’s longtime socialist president, Hugo Chávez, El Frío was expropriated in 2009. The research station was abruptly closed, and a Spanish biologist who had run it was barred from the ranch.

Now the hatchery hangs on by a thread, largely because of the perseverance of Mr. Rattia. After the government takeover, Mr. Rattia said, he was reassigned to work as an auto mechanic, something in which he had no experience. After several months, when the crocodiles began dying, he appealed to the ranch’s new managers to let him return to the hatchery.

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A meal of horse meat.Credit
Meridith Kohut for The New York Times

He has been running it almost single-handedly ever since.

He has no money to replace a faulty thermostat in the incubator used to hatch crocodile eggs. When the thermostat malfunctioned last year, the incubator overheated, and dozens of eggs were destroyed. A freezer used to store meat for the animals broke about a year and a half ago and has not been replaced.

Mr. Rattia spends much of his time fishing to provide food for the animals in the hatchery, which include 155 young crocodiles and 1,300 Arrau turtles, another endangered species. Although he makes only about slightly more than the minimum wage, he digs into his own pocket to buy vitamins to supplement the animals’ food.

“They don’t see the value of this,” Mr. Rattia said. “I feel that the day I go is the day the hatchery ends.”

Officials at the Environment Ministry in Caracas, the capital, turned down requests for interviews, but the environment minister, Miguel Rodríguez, recently defended the government’s stewardship when he visited the ranch to release 45 young crocodiles.

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Mr. Velasco conducting a night mission.Credit
Meridith Kohut for The New York Times

“The construction of socialism would not be compatible if we don’t also preserve nature,” Mr. Rodríguez was quoted as saying in a government newspaper. He said that a majority of releases had occurred after Mr. Chávez first took office in 1999, suggesting that the government had given the program new impetus. Much of that activity, however, was carried out by private ranchers and foundations, conservationists said.

There are six facilities in Venezuela involved in raising Orinoco crocodiles for release in the wild. Most collect eggs laid by wild crocodiles, as El Frío does, or from crocodiles kept in small, enclosed lagoons for breeding. They incubate the eggs and raise the hatchlings until they are about a year old, when they are large enough to have a good chance of surviving on their own.

Humans continue to be the crocodiles’ greatest enemy. Poor rural residents often kill them, out of fear that they will attack people, conservationists said. They also take their eggs for food and capture baby crocodiles to sell as pets.

Conservationists said the effort to save the crocodile was undermined by the absence of game wardens to patrol the rivers where they live.

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The fearsome gaze of the crocodile, which was nearly hunted to extinction decades ago.Credit
Meridith Kohut for The New York Times

Private efforts to save the Orinoco crocodile also face serious challenges. One, on the Masaguaral Ranch, led to the country’s first crocodile hatchery in the late 1980s, and today it produces about 200 baby crocodiles a year, more than any other facility.

But the government has long been antagonistic to large landowners, casting them as enemies of its revolutionary program. After the takeover of El Frío and some other ranches, the threat of expropriation is a constant worry.

Mr. Hernández, the director of the environmental foundation, said the government had virtually cut all communication with such independent programs. He said that each year he submitted requests for permission to release crocodiles in a national park on the Capanaparo River, and that the government had repeatedly failed to respond.

“In theory, they want to do everything, but then they don’t do it,” Mr. Hernández said.

Nonetheless, the potential for public-private cooperation can be seen at another government-run ranch, called El Cedral. With financing from a private foundation started by a former Environment Ministry official, the ranch last year created a crocodile hatchery, where there are now about 90 baby crocodiles being raised in well-maintained tanks.

Pedro González, 57, who works at the hatchery, recalled how his father used to hunt crocodiles at night from a canoe, using a harpoon, the traditional method here.

“I am remaking what my father devoured,” Mr. González said.

A version of this article appears in print on December 26, 2013, on Page A4 of the New York edition with the headline: Venezuela’s Fitful Effort to Save a Scaly Predator. Order Reprints|Today's Paper|Subscribe